Chopper body

ABSTRACT

Apparatus for chopping sized glass fiber filaments comprising two co-operating parallel rollers between which the filaments are passed one roller having a series of spaced blades projecting from its surface; gaps being provided in this roller between successive blades to reduce the area of this roller in contact with the filaments at any given time.

United States Patent Lomas [4 June 13, 1972 [54] CHOPPER BODY 3,340,7579/1967 Rudszinat ..83/674 X 3,424,043 1/1969 Martin ..83/65 9 X EricEllis Lomfls, Wallasey, England 2,829,694 4/1958 Jarvis ..83/674 x I 73]Fibreglass 'l Ravenhead FOREIGN PATENTS OR APPLICATIONS Helens,Lancashire, England 4,90 19 6 B g 1968 8 2/ 0 Great ritam 83/346 [2 1 1Primary Examiner-Andrew R. .luhasz Assistant Examiner-Leon GildenAttorney-Birch, Swindler, McKie & Beckett Foreign Application PriorityData Aug. 22, 1967 Great Britain ..38,653/67 [57] ABSTRACT Apparatus forchopping sized glass fiber filaments comprising [52] U.S. Cl ..83/347,83/674, 83/698 two co-operating parallel rollers between which thefilaments [51] Int. Cl. .JB23d 25/12, 823d /00 are passed one rollerhaving a series of spaced blades project- [58] Field of Search ..s3 343,346, 347, 659, 665, ng m its surface; g p being provided in h r llerbetween 83/674, 698, 561 successive blades to reduce the area of thisroller in contact with the filaments at any given time. .[56] ReferencesCited sclaims, 9 w g Figures UNITED STATES PATENTS 2,829,689 4/1 958Jarvis ;.s3/ 34 x 22 32a 17! 15 23 325, 4e 54 V 78 P P P g 52PATENTEUJUH 1 3 I972 SHEET 3 BF 3 F/GB.

CHOPPER BODY This invention relates to the chopping of continuousfilaments into short lengths and has particular application to thechopping of continuous glass fiber strands.

It is known to chop continuous filaments into short lengths bypassingthe filaments between two parallel rollers one of which has a series ofcutters projecting from the periphery thereof and the other of which iscovered with a resilient material. The cutters, particularly those usedfor severing filaments such as glass strands, comprise very thin bladesand the known roller bodies for supporting these very thin bladescomprises a solid roller body with thin radial slots into which thecutter blades are inserted as a forced fit". The depth of the slots issuch that only a very small amount of the cutter blade projects from theperiphery of the cutter roller so that maximum support is afforded tothe cutter blades. The roller coated with the resilient material is abacking roller and the two rollers are loaded towards one another androtated with uniform peripheral speeds so that the continuous filamentsare gripped therebetween, passed through the nip with a linear speedequal to the peripheral speed of the rollers, and severed by a cutterblade only when the cutter blade is forced into the backing roller.

This type .of chopper has a very limited life, particularly whenchopping coated filaments, such as glass fiber strands which are coatedwith a size, because the rollers tend to pick up size from glass strandspassing therebetween and become coated with the size. The rollingpressure between the two rollers and the action of the blades working"the surface of the backing roller create heat which is easily dissipatedfrom the surface of the resilient roller but is retained in therelatively solid, usually metallic, body of the cutter roller and as thetemperature of the cutter roller increases size deposited thereon issolidified. The'solidified deposit of size increases the rollingpressure between the rollers and thus increases the temperature of thechopper body so that the build up of further size deposits on the rolleris facilitated.

The build up of size deposit on the cutter roller greatly reduces theoperating life of the cutter and in practice frequent replacement of thecutter rollers is necessary.

SUMMARY OF THE INVENTION The object of the present invention is toprovide a chopper body construction which is not readily susceptible tofailure by solidification of deposits thereon and which thereby affordsa longer effective life than known chopper constructions. I According tothe present invention apparatus for chopping continuous filamentscomprises a rotatable chopper body carrying a plurality of chopperblades whose cutting edges are arranged to describe a cylinder ofrevolution, a rotatable backing roller mounted so that there isinterference between the periphery of the Additionally and said cylinderof revolution sufficient to enable said blades to chop filaments againstthe roller, feeding means to feed continuous filaments between thechopper body and the backing roller, and drive means to rotate saidchopper body so that successive blades respectively make successivechops, wherein said chopper body comprises support means arranged tosupport said blades in circumferentially spaced relationship and toprovide a gap between successive blades such that contact between atleast part of the periphery of the backing roller and the chopper bodyis avoided between of said gap.

The present invention thus envisages a chopper body having gaps betweensuccessive cutter blades so that the area of the chopper body contactingthe filaments, and thereby susceptible to contamination by the coatingon the filaments, is reduced and the mass of the chopper body isreduced. Additionally the surface area of the chopper body exposed toatmosphere can be increased and the construction can permit air to beentrained in the gaps so that the chopper body is efsuccessive chops byreason 2 fectively cooled and solidification of the size contacting theroller parts is reduced.

The gaps between the chopper blades may comprise grooves or slots cutinto the curved surface of asolid chopper body or the chopper body maycomprise a fabricated structure.

Thus, said support means may comprise at least two support elementsspaced apart along the axis of rotation of the chopper body, and theremay be provided a further support element arranged to support eachchopper blade at a'posi'tion substantially central of the blade.Conveniently said support elements are mounted on a common shaft.

The chopper body may include end plates, and retaining means associatedwith saidend plates and said chopperblades adapted to prevent radialmovement of said blades relative to the chopper body.

When the chopper blade is thin, or unsupported over lengths which permitflexing thereof, each chopper blademay be mounted against at least onesupport plate, and may be sandwiched between a pair of support plates.

The term filament" when used in the present invention includes anysingle filament or strand, roving ribbon or rope made up of a number offibers DESCRIPTION OF THE DRAWINGS The present invention will now bedescribed further by way of example with reference to the accompanyingdrawings in which:

FIG. 1 shows a vertical section through a filament chopping arrangementon the line II, II of FIG. 2,

FIG. 2 shows a center line section through the chopper arrangement onthe line III, III of FIG. 1,

FIG. 3 is an end view of a cutter assembly support member,

FIG. 4 shows an end view of an end flange,

FIG. 5 shows a section on the line IV, IV of FIG. 4,

FIG. 6 shows an exploded view of a cutter assembly,

FIG. 7 is an end view of a cutter assembly,

FIG. 8 is a vertical section through a modified form of chopper body,and

FIG. 9 is an end view of the body shown in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the apparatus illustrated inFIG. 1 for chopping continuous glass strands the strands pass betweendriven rollers l l 12 which direct said strands between a backingroller13 and a chopper body 14.

The chopper body 14 comprises a hollow tubular shaft 15, with reducedends 1 6, 17 upon which a first support member 18, having a boss 19, issecured by a pin 20. The support member 18 has eight radial slots 2]equally spaced about its periphery and the slots 21 are of equal depthso that the roots thereof lie on a common circle concentric with theaxis of shaft 15. A second support member 22, identical with supportmember 18 and having a boss 23 and radial slots 24, is secured on shaft15 by a pin 25 so as to lie in spaced parallel relationship with supportmember 18 and with its slots 24 aligned with the slots 21 in supportmember 18 in planes passing through the axis of shaft 15.

Cutter assemblies 30 are inserted into the aligned slots 21, 24 so as tolie parallel to the axis of shaft 15 and each cutter assembly comprisesa support plate 31, having a base 32, a cutter blade 33, and a backingplate 34. The base 32 of support plate 31 extends outwardly from oneface of plate 31 to form a seat for the lower edge of the blade 33 andthe lower edge of the backing plate 34. The plate 31, blade 33 and plate34 have the same length, which length is equal to the distance betweenthe outside plane faces of support members 18 and 22 when said membersare secured on shaft 15 but the base 32 extends outwardly beyond theends of plate 31 to form location lugs 32a for the assemblies 30.

part of a support element used in When a cutter assembly 30 is insertedinto aligned slots 21 and 24, said assembly being a relatively tight fitin said slots 21, 24, the slots 21, 24 contain the assembly againstdisplacement normal to the plane of the blade 33 and thus each blade 33is supported along the whole of its lower edge and over the major partof its plane faces. To retain the blade 33 and plate 34 against relativedisplacement in the plane of the blade 33 two pegs 35, 36 are passedthrough holes 37, 38 respectively in plate 31, holes 39, 40 respectivelyin blade 33, and holes 41, 42 respectively in plate 34.

With all the cutter assemblies 30 located in their respective slots 21,24 in the support members 18, 22 the lugs 32a of the base 32 projectoutwardly from the support members 18, 22 and an end flange 43, havingan annular recess 44, is secured onto support member 18 by screws 45with the lugs 32a projecting from member 18 engaged in the recess 44. Anend flange 46 with an annular recess 47 is, in like manner, secured onsupport member 22 by screws 48 with the lugs 32a projecting from supportmember 22 located in the annular recess 46. It will thus be seen thatthe end flanges 43 and 46 restrain the cutter assemblies 30 againstradial displacement.

The backing roller 13 comprises a solid core 50 with a resilient sleeve51 secured thereon and said core 50 has reduced ends 50a and 50b. Thereduced ends 50a and 50b are supported in bearings presented by plates Pforming part of the machine frame and plates P also present bearings forthe reduced ends 16 and 17 of the shaft 15.

The apparatus is driven by a gear wheel 52, rotated by a drive means(not shown) which meshes with a gear wheel 53 secured on reduced end5012 of core 50 and gear wheel 53 in turn meshes with a gear wheel 54secured on reduced end 17 and by this means backing roller 13 andchopper body 14 are rotated in opposite directions. The backing roller13 is mounted relative to the chopper body so that there is interferencebetween the periphery of the backing roller and the cylinder ofrevolution described by the cutting edges of the chopper blades 33.

The diameter of roller 13 is greater than the effective diameter ofchopper body 14 i.e. that diameter swept by the outermost faces of thecutter assemblies, so that the blades 33 engage different parts ofroller 13 to avoid excessive wear in limited regions of roller 13 andthe gear wheels 52 and 53 are so selected that the peripheral speed ofroller 13 is equal to the peripheral speed at the effective diameter ofchopper body 14.

In operation gear wheel 52 transmits drive through gear wheel 53 andgear wheel 54 to rotate backing roller 13 and chopper body 14 and drivenrollers 11, 12 pass the endless strands to be chopped into the nipbetween roller 13 and body 14. The filaments are driven at uniform speedand the peripheral speed of the effective diameter of roller 13 and body14 are equal to the linear speed of the strands. As the chopper body 14rotates the strands are caught between the cutter assemblies of body 14and the backing roller 13; there is pressure contact between the cutterassemblies and the backing roller 13 and the projecting cutter edge ofblades 33 sever the strands.

It will be seen that the space between the support members 18 and 22provides a gap between cutter assemblies such that contact between partof the periphery of the backing roller 13 and the chopper body isavoided between successive chops by reason of this gap.

The cutter assemblies are largely exposed to the surrounding atmosphereand have the form of paddles which stir the surrounding atmosphere sothat the chopper assemblies remain relatively cool, and as the parts ofthe chopper body which normally contact the endless filaments are thecutting edge of the blade 13 and the outermost surfaces of the plates 31and 34, and as these surfaces are cooled, the solidification of cuttingdeposits on the chopper body 14 is reduced.

The chopper body shown in FIG. 8 comprises a shaft 60 on which endsupport elements 61 and 62 are mounted at positions spaced along theshaft. The elements 61 and 62, which are identical, are generallydisc-like in form but with projecting bosses 63 and 64 respectivelyhaving diametrical holes in which pins 65 and 66 are fitted to securethe support elements to the shaft 60, the latter having correspondingholes through which the pins pass. Associated with the support elements61 and 62 are respective adaptor discs 67 and 68 of the same outsidediameter as the support elements and with a central hole such that thediscs 67 and 68 fit over the bosses 63 and 64. The adaptor discs 67 and68 are secured to the support elements 61 and 62 by screws passingthrough arcuate slots in the discs and threaded into holes in thesupport elements, the screws, holes and slots not being shown in thedrawing.

Mounted on the shaft 60 in a position substantially midway between theend support elements 61 and 62 is a central support element 69, which isgenerally disc like in form but with a projecting boss 70. A pin 71 isfitted in a diametrical hole in the boss and passes through acorresponding hole in the shaft 60 to secure the support element to theshaft. Associated with the central support element 69 is an adaptor disc72, like the discs 67 and 68, having a central hole such that it fitsover the boss 70. The disc 72 is secured to the element 69 by means ofscrews through arcuate slots in the disc and threaded into holes in thesupport element. The outside diameter of the disc 72 and central supportelement 69 is the same as that of the end support elements 61 and 62 andadaptor discs 67 and 68.

The support elements 61, 62, and 69 and the adaptor discs 67, 68 and 72have equi-spaced radially extending slots 73 in their peripheries (seeFIG. 9). These slots are essentially similar to the slots 21, 24previously described but are provided in greater number, and aresomewhat narrower for a reason which will become apparent. The supportelements and adaptor discs are so oriented that the peripheral slots 73therein are aligned in a direction parallel to the shaft 60, i.e. aseries of sets of aligned slots is provided, each set comprising oneslot in each of the support elements and adaptor discs. A cutter orchopper blade 74 is fitted in each set of aligned slots with the bladeslinear cutting edge facing outwardly and projecting from the slots. Thepositioning of the support elements and adaptor discs along the shaft 60is such that each blade 74 is supported adjacent its ends by the endsupport elements 61 and 62 and their associated adaptor discs 67 and 68,and substantially centrally along its length by the central supportelement 69 and its associated adaptor 72. In this manner a series ofchopper blades 74 are carried in circumferentially spaced relationshipround the chopper body, the spaces between the central support and theend supports providing gaps between successive blades.

The slots 73 are narrower than the slots 21, 24 previously describedbecause the slots 73 accommodate only a chopper blade 74, whereas theslots 21, 24 accommodate a chopper blade 33 together with support plates31, 34 between which the blade is sandwiched.

Each of the blades 74 used in the embodiment shown in FIG. 8 is providedwith end slots or recesses 75 and 76. Disclike end plates or caps 77 and78 are provided with ring projections 79 and 80, which fit in therecesses 75 and 76 respectively, and thereby hold the blades againstmovement radially outwards. The end plates or caps 77 and 78 havecentral holes such that they fit over bosses 81 and 82 respectivelyprovided on the end support elements 61 and 62, the end plates beingsecured to the end support elements by mans of screws 83 and 84. Theend-most part of the periphery of the end support elements 61 and 62 isof reduced diameter to permit inward projection of the rings 79 and onthe end plates.

The operation of the chopper body shown in fig. 8 is essentially thesame as previously described, the shaft 60 being rotated and the blades74 successively chopping filaments against a rotatable backing roller.

In the drive arrangement previously described, the chopper body and thebacking roller are positively driven in opposite directions by means ofappropriate gears. lf preferred, the chopper body alone may be directlydriven by the drive means, and the backing roller may be mounted forfree rotation and may be rotated by frictional contact with the rotatingchopper body.

What we claim is:

1. Apparatus for chopping continuous filaments comprising a rotatablechopper body having a pair of disc-shaped blade support members alongthe axis of rotation thereof, each of said support members havingradially extending blade receiving slots in circumferentially spacedrelationship, said slots of one of said support members being alignedwith said slots on the other of said support members in planes passingthrough the axis of rotation,

a plurality of chopper blades mounted in said slots and supported attheir ends by said slots such that the cutting edges of said bladesprotrude from said slots to describe a cylinder of rotation of thediameter greater than the diameter of said support members,

blade support plate means associated with each of said chopper bladesand coextensive therewith, said blade support plate means comprising abase member against which the base of said blade is seated and a backingmember against which a side of said blade is seated, said backing memberincluding means engaging said blade and locking said blade againstrelative movement with respect to said support plate means, said bladeand said support plate means being received in said slots,

a pair of end plates on said chopper body for locking said bladesagainst radial and axial movement, said end plates engaging said bladesupport plate means,

a rotatable backing element having a resilient surface mounted on aparallel axis adjacent said chopper body and spaced from said chopperbody such that there is interference between the periphery of saidcylinder of rotation described by said cutting edges and said backingroller sufficient to enable said blade to chop filaments against saidbacking roller while direct contact between said chopper body and saidbacking roller is avoided,

means for feeding continuous filaments between said chopper body andsaid backing roller, and

means rotating said chopper body.

2. Apparatus as set forth in claim 1 wherein each of said blades issandwiched between a pair of backing members.

3. Apparatus as set forth in claim 1 wherein each of said bladesincludes at least one opening therethrough and wherein said meansengaging said blades includes projections on said backing plates forengaging said openings to lock said blade against movement relative tosaid support plate means.

1. Apparatus for chopping continuous filaments comprising a rotatablechopper body having a pair of disc-shaped blade support members alongthe axis of rotation thereof, each of said support members havingradially extending blade receiving slots in circumferentially spacedrelationship, said slots of one of said support members being alignedwith said slots on the other of said support members in planes passingthrough the axis of rotation, a plurality of chopper blades mounted insaid slots and supported at their ends by said slots such that thecutting edges of said blades protrude from said slots to describe acylinder of rotation of the diameter greater than the diameter of saidsupport members, blade support plate means associated with each of saidchopper blades and coextensive therewith, said blade support plate meanscomprising a base member against which the base of said blade is seatedand a backing member against which a side of said blade is seated, saidbacking member including means engaging said blade and locking saidblade against relative movement with respect to said support platemeans, said blade and said support plate means being received in saidslots, a pair of end plates on said chopper body for locking said bladesagainst radial and axial movement, said end plates engaging said bladesupport plate means, a rotatable backing element having a resilientsurface mounted on a parallel axis adjacent said chopper body and spacedfrom said chopper body such that there is interference between theperiphery of said cylinder of rotation described by said cutting edgesand said backing roller sufficient to enable said blade to chopfilaments against said backing roller while direct contact between saidchopper body and said backing roller is avoided, means for feedingcontinuous filaments between said chopper body and said backing roller,and means rotating said chopper body.
 2. Apparatus as set forth in claim1 wherein each of said blades is sandwiched between a pair of backingmembers.
 3. Apparatus as set forth in claim 1 wherein each of saidblades includes at least one opening therethrough and wherein said meansengaging said blades includes projections on said backing plates forengaging said openings to lock said blade against movement relative tosaid support plate means.